The controller of the conventional power inverter circuit is described by FIG. 11. In FIG. 11, when the switch 81 is on, the power converter circuit 8 supplies electric power from the power supply 101 to the load 102 through the electric the reactor 82. When the switch 81 is off, the power converter circuit 8 emits energy saved to the reactor 82. Thereby, electric power is supplied to the load 102.
Note that, in FIG. 11, an output side of the power converter circuit 8 is provided with the smoothing capacitor 84.
The controller 9 of the power converter circuit 8 is comprised of the A/D converter circuit 91, the drive timing value generation circuit 92 and the driving signal generation circuit 93.
The A/D converter circuit 91 inputs output voltage eo of the power converter circuit 8, and converts an input signal into a digital signal.
The A/D converter circuit 91 outputs converted digital signals to the drive timing value generation circuit 92.
The calculation result D in the drive timing value generation circuit 92 is sent out to the driving signal generation circuit 93. The driving signal generation circuit 93 generates a control signal (switch driving signal DSW) based on the calculation result D, and drives the switch 81 by this control signal.